JPH0562163B2 - - Google Patents

Description

[Detailed Description of the Invention] "Industrial Application Field" The present invention relates to a wave-dissipating structure installed to dissipate waves that attack a port or a coast, and particularly to a wave-dissipating structure installed in a deep offshore area. The present invention relates to a suitable wave-dissipating structure.

``Conventional technology'' In recent years, in addition to calming the waters around ports and coasts, wave-dissipating structures have been constructed in large offshore waters such as these coasts, with the aim of maintaining the scenery of these coasts and preserving the water quality of these waters. It has become necessary to install a physical body.

Therefore, the present applicant has provided a wave-dissipating structure shown in FIGS. 6 and 7 as one that satisfies the above object. Reference numeral 1 in the figure is a wave-dissipating structure, which is installed in the ocean offshore. This wave-dissipating structure 1 is
Concrete blocks 2, 2 formed in an annular shape
... are arranged alternately in a staggered manner in a direction parallel to the water surface W, and are also stacked in a vertical direction, and these are connected to each other by a fixing means 3, and their bases are The end portion is installed on the seabed G and fixed to the base 4. The fixing means 3 is a concrete block 2 disposed below.
The groove formed on the lower part of the concrete block 2 placed above is fitted into the groove formed on the upper surface, and the protrusion provided on the upper surface of the lower concrete block 2 is made to fit into the groove formed on the lower part of the concrete block 2 placed above. The concrete block 2 is configured so that it fits into a recess formed on the lower surface of the block 2, or is constructed by having each concrete block 2 inserted through a pile erected perpendicularly to the sea surface W.

In this case, by arranging five rows of annular blocks in the wave intrusion direction, a sufficient wave-dissipating effect could be obtained.

``Problems to be Solved by the Invention'' However, in the conventional wave-dissipating structure described above, there was a problem in that when the row of annular blocks was reduced, the wave-dissipating effect decreased accordingly.

Therefore, the applicant of the present invention conducted further research and improved the wave-dissipating effect by improving the performance of the annular blocks, thereby reducing the number of annular blocks arranged in the wave intrusion direction.

The present invention has been made in view of the above-mentioned problems, and aims to provide a wave-dissipating structure that has higher wave-dissipating efficiency than conventional wave-dissipating structures and can reduce manufacturing and construction costs. The purpose is

"Means for Solving the Problems" The present invention solves the above problems by fixing a plate inside an annular block.
In this case, it is desirable that the plate extends in a direction perpendicular to the wave intrusion direction and is shifted from the center of the annular block to the side opposite to the wave intrusion side.

"Function" According to the wave-dissipating structure of the present invention, since the plate material is disposed within the annular block, it partially obstructs the movement of waves in the vertical direction, and the plate material is located at the center of the annular block. By being eccentrically arranged on the side opposite to the side where the waves enter, a jet stream is generated efficiently and the energy of the waves is reduced.

"Example" The present invention will be described below with reference to FIGS. 1 to 5. These drawings show one embodiment of the present invention, and in these drawings, the same elements as those shown in the prior art are as follows:
The same reference numerals are used to omit the explanation.

Block 2 constituting the wave-dissipating structure 1 of the present invention
As shown in FIG. 1, the block main body 2a is formed in an annular shape from a material such as concrete, and is arranged such that both ends thereof are fixed between the inner wall surface of the block main body 2a and the inner diameter of the block main body 2a. It is composed of a rectangular plate 2b having a width of about 30% of the width of the rectangular plate 2b. Further, as shown in FIG. 2, in this embodiment, the plate material 2b extends in a direction perpendicular to the wave intrusion direction (from the right side to the left side with respect to the plane of the paper), and the plate material 2b extends in the direction perpendicular to the wave intrusion direction (from the right side to the left side with respect to the plane of the paper). It is placed slightly offset from the center on the side opposite to the side where the waves enter. Further, as shown in FIG. 3a, the plate material 2b
may be placed parallel to the bottom surface of the block body, or it may be placed at an angle with one end aligned with the bottom surface of the block body, as shown in Figure 3b. Also good. In addition, plate material 2
b may be manufactured separately and fixed inside the annular block main body 2a,
Alternatively, it may be a concrete block integrated with the block main body 2a.

In this embodiment, when the annular block 2 is installed underwater at a depth of 20 m, the outer diameter of the block body 2a is 10 m, and the distance between the center points of adjacent concrete blocks 2 is 10 m. The wave-dissipating structure of the present invention has three rows of annular blocks 2 in the X direction where the waves attack, as shown in FIG. It is constructed by stacking a predetermined number of stages in the height direction of W (direction perpendicular to the paper surface).

Next, the operation of the wave-dissipating structure according to the present invention configured as described above will be explained together with an example of its implementation.

First, after leveling the seabed ground G on which the wave-dissipating structure 1 is installed, the base 4 made of steel, geotextile structure, etc. is constructed on this seabed ground G.
Next, Block 2, which was manufactured on land near the factory or installation site, is transported to the offshore site, where it is placed in a predetermined position by a crane ship, etc., and workers enter the sea to position each block. The wave-dissipating structure 1 is completed by connecting blocks 2, 2, . . . and stacking them one after another.

In this way, the wave-dissipating structure 1 is constructed by installing the blocks 2 in the water using a crane ship or the like and stacking them without waste, so it is different from the conventional structure in which wave-dissipating blocks are piled up arbitrarily. Compared to the conventional type, which has a wide base and is expected to require a huge number of blocks, it can be easily constructed even in deep offshore areas, and the construction equipment is simplified. result,
Construction costs etc. can be significantly reduced.

The wave-dissipating structure 1 converts the circular motion of seawater into a direction horizontal to the sea surface W through the vertical gaps between the blocks 2, 2, and rectifies it. The gaps disturb the direction of travel of the waves, and the waves interfere with each other, reducing the energy of the waves.

Furthermore, since this wave-dissipating structure 1 has a plate member 2b disposed within an annular block 2, this partially obstructs the movement of waves in the vertical direction, and the plate member 2b is arranged in an annular block 2. By being slightly shifted from the center of the wave to the side opposite to the wave intrusion direction, a jet flow is efficiently generated, and the wave energy can be further efficiently reduced.

Here, the results of an experiment conducted using a model of the wave-dissipating structure of the present invention are shown in FIG.

This experiment consisted of (a) a wave-dissipating structure in which three annular blocks 2 each having plate materials 2b arranged in the wave intrusion direction were arranged, and (b) only an annular block main body 2a. Wave-dissipating structure when blocks (without plate 2b) are arranged in three rows in the wave intrusion direction, (c)
Wave-dissipating properties, transmittance, and reflection are shown for three cases: a wave-dissipating structure in which five blocks (without plate material 2b) consisting of annular block bodies 2a are arranged in five rows in the wave intrusion direction. This is to find the relationship with efficiency. In addition, the conditions for the location where the wave-dissipating structure is installed are: water depth = 20 m, wave height = 3
It was set as m.

As shown in FIG. 5, the experimental results show that the wave-dissipating structure a of the present invention having the plate material 2b is
It has a transmission efficiency that is sufficiently lower than that of the wave-dissipating structure b, which is made up of only the annular block bodies 2a, and is approximately the same as that of the wave-dissipating structure c, which has five rows of blocks that are made only of the annular block bodies 2a. It has a transmittance and a reflectance of
This shows that it has a sufficient wave-dissipating effect.

As described above, since the wave-dissipating structure 1 of the present invention has the plate material 2b disposed within the annular block main body 2a, it has been proven that jet flow is efficiently generated and wave energy is reduced. The wave-dissipating efficiency can be further increased than that of the wave-dissipating structure. As a result, the number of annular blocks can be reduced,
The manufacturing cost, construction cost, etc. of the wave-dissipating structure can be significantly reduced.

In addition, the construction method described above can be used, making construction easy even in deep offshore areas, keeping construction costs low, and providing sufficient wave dissipation even in deep water areas with high waves. It can be a wave-dissipating structure that is expected to be effective.

Further, by disposing the beam-shaped plate material 2b inside the annular block main body 2a, this serves as a reinforcing member, and the rigidity of the block 2 is improved, making it possible to form a strong structure.

Note that other embodiments or technical matters other than those described above will be described below.

(i) It goes without saying that the annular block 2 of the present invention is not limited to the outer diameter dimensions shown in the above embodiments, but can be appropriately modified in design depending on various conditions of the place where it is installed.

(ii) The plate material 2b of the present invention is not limited to that shown in the above embodiments, and its width, thickness, shape, mounting position, etc. may be changed as appropriate.

(iii) The wave-dissipating structure 1 of the present invention is not limited to the above-mentioned embodiments, and the arrangement and number of stages of the blocks 2 can be changed as appropriate depending on various conditions of the place where the blocks 2 are installed. Of course.

(iv) The wave-dissipating structure 1 of the present invention is not limited to the above-mentioned embodiments, and for example, the wave-dissipating structure 1 can be constructed by installing a portion having a wave-dissipating effect only near the sea surface W, raising the base 4, and constructing the block 2. It is also possible to have a configuration in which the number of stages is reduced.

"Effects of the Invention" As described above, according to the present invention, the annular blocks are arranged in a staggered manner in a direction parallel to the water surface, and the wave-dissipating blocks are stacked vertically. Since this is a structure in which a plate is fixed inside the annular block, it partially obstructs the movement of waves in the vertical direction, and also prevents the plate from being eccentric from the center of the annular block. By arranging it, a jet stream can be efficiently generated and wave energy can be efficiently reduced. As a result, the number of annular blocks can be reduced, and the manufacturing and construction costs of the wave-dissipating structure can be significantly reduced.

[Brief explanation of the drawing]

1 to 5 show an embodiment of the present invention, in which FIG. 1 is a perspective view of an annular block constituting a wave-dissipating structure, FIG. 2 is a plan view of FIG. 1, and FIG. Figures 3a and b are side sectional views of Figure 1, Figure 4 is a plan view of a wave-dissipating structure in which blocks are arranged in three rows in the wave intrusion direction, and Figure 5 is an experiment using a model. The charts showing the results, Figures 6 and 7, show the conventional technology, and Figure 6 is a plan view of the wave-dissipating structure.
FIG. 7 is a side sectional view thereof. W... Sea surface (water surface), G... Seabed (bottom), 1...
... Wave dissipating structure, 2 ... Block, 2a ... Annular block body, 2b ... Plate material, 3 ... Fixing means.

Claims (1)

[Scope of Claims] 1. A wave-dissipating structure formed by annular blocks arranged in a staggered manner in a direction parallel to the water surface and stacked in a vertical direction,
A wave-dissipating structure characterized in that a plate material is fixed to the inside of the annular block. 2. The plate material extends in a direction perpendicular to the wave intrusion direction, and is arranged offset from the center of the annular block to the side opposite to the wave intrusion side. Claim 1
Wave-dissipating structure described in section.